The present invention relates to a bus-bar wiring board assembled in an electric connection box etc. installed in an automobile or other vehicle.
A bus-bar wiring board assembled in an electric connection box etc. installed in an automobile or other vehicle has conventionally been produced by punching out a bus-bar pattern for use as electric wiring from a conductive metal sheet by a forwarding press one pattern at a time. For example, as shown in FIG. 1, a bus-bar pattern 2 laid out in a predetermined shape is punched out from a conductive metal sheet 1 having a width W.
The bus-bar pattern 2 includes bus-bars for a plurality of circuits and is punched out in a state connected by bridges 3 at different positions so that the plurality of circuits do not come apart after being punched out. The bridges 3 are cut after the bus-bar pattern 2 is stacked on an insulating board so as to separate the bus-bar pattern 2 into the bus-bars of the respective circuits. The portions of the tabs 4 are perpendicularly bent at the positions of the broken lines to stand upright prior to the pattern being stacked on the insulating board.
The above bus-bar pattern 2 is normally formed to a contour to fit in the surrounding walls of a case of the electric connection box, but in the case of a ground circuit etc., for grounding to the chassis, a projecting terminal piece 5 is provided projecting from the surrounding walls of the case of the electric connection box to the outside in some cases.
In such a case, in the past, since the projecting terminal piece 5 and the bus-bar pattern 2 were punched out as one piece from the conductive metal sheet 1, as shown in FIG. 1, there was the problem that large material scraps 6 (hatched portion) were generated from the conductive metal sheet 1 and the conductive metal sheet could not be effectively used.
An object of the present invention is to provide a bus-bar wiring board which can reduce waste by effectively using a conductive metal sheet and can reduce the production costs.
Another object of the present invention is to provide a method of producing a bus-bar wiring board which can reduce waste by effectively using a conductive metal sheet and can reduce the production costs.
A bus-bar wiring board of the present invention comprises a bus-bar pattern for electric wiring formed to a predetermined shape and a bus-bar piece separately formed from the bus-bar pattern and electrically connected and secured to the bus-bar pattern.
In the bus-bar wiring board of the above configuration, the above bus-bar pattern may have one of an integrally formed male projecting portion and female recessed portion, the bus-bar piece may have the other of the integrally formed male projecting portion and female recessed portion of a shape complementarily fitted with the one of the male projecting portion and female recessed portion formed in the bus-bar pattern, and the bus-bar piece may be secured to the bus-bar pattern by fitting the one of the male projecting portion and female recessed portion into the other.
Further, in the bus-bar wiring board of the above configuration, the one and the other of the male projecting portion and female recessed portion may be formed by press working.
The method of producing a bus-bar wiring board of the present invention includes a bus-bar pattern punching step for punching out a bus-bar pattern for electric wiring laid out to a predetermined shape from a conductive metal sheet; a bus-bar piece punching step for punching out a bus-bar piece laid out to a predetermined shape at a remaining space of the conductive metal sheet; and a connecting step for electrically connecting and securing the bus-bar pattern punched out by the bus-bar punching step and the bus-bar piece punched out by the bus-bar piece punching step.
In the method of production of the above configuration, the bus-bar piece punching step may be carried out simultaneously with the bus-bar pattern punching step.
Further, the method of production of the above configuration may further comprise a first fitting portion forming step for forming one of a male projecting portion and female recessed portion as a first fitting portion at the bus-bar pattern and a second fitting portion forming step for forming the other of the male projecting portion and female recessed portion as a second fitting portion complementarily fitting with the first fitting portion at the bus-bar piece, the first fitting portion and second fitting portion being connected and secured by press-fitting by a press in the connecting step.
Further, in the method of production of the above configuration, the first fitting portion forming step may be carried out simultaneously with the bus-bar pattern punching step and the second fitting portion forming step may be carried out simultaneously with the bus-bar piece punching step.
Further, in the method of production of the above configuration, in the connecting step, the bus-bar pattern and the bus-bar piece may superposed and recessed portions formed integrally by press-working to connect and secure the two.
Further, in the method of production of the above configuration, the bus-bar piece punching step may be carried out simultaneously with the bus-bar pattern punching step and, in the connecting step, the bus-bar pattern and the bus-bar piece may be superposed and recessed portions formed integrally by press-working to connect and secure the two.